Comparative study of structural properties and biological activities of polysaccharides extracted from Chroogomphus rutilus by four different approaches.

Extraction processes significantly alter the structural and functional properties of polysaccharides. In this study, we extracted polysaccharides from Chroogomphis rutilus fruiting bodies (designated as CRP) using four methods, including hot water, ultrasound, microwave and sequential ultrasound-microwave, and designated these polysaccharides as CRP-H, CRP-M, CRP-U and CRP-UM, respectively. All CRPs were heteropolysaccharides with semblable monosaccharide types of glucose, mannose and galactose, mainly constituted of α-d-glucopyranosyl-(1 â†’ 4). The extraction processes significantly affected the molecular weights, monosaccharide proportions, glycosidic bond ratios, branching degrees, triple-helix conformation and surface morphology of the CRPs. Among them, CRP-UM showed the highest yield and most potent antioxidative capacity in vitro and in HL-7702 cells, but the weakest activation of immunostimulatory response in RAW264.7 cells. In contrast, CRP-H exhibited the lowest yield but strongest immunostimulatory activity. Overall, microwave extraction could be utilized as a general and practical CRP extraction approach, based on its relatively high yield and bioactivities.

Preparation of porous chitosan gel beads for copper(II) ion adsorption.

In this paper, chitosan porous beads were prepared by using a phase inversion technique, and then used for the adsorption and removal of copper(II) ions. The porosity, diameter and other characteristics were characterized. With the increase of chitosan and NaOH concentration used to prepare the beads, the amount of adsorbed Cu2+ per gram of the beads decreased. A maximum adsorption amount was observed at a pH value of 6.0 for the cross-linked porous chitosan beads. The amount of the adsorbed Cu2+ increased with the Cu2+ concentration used in the adsorption experiments. By the relationship of the ratio of the equilibrium Cu2+ concentration in the solution (C(e)) to the adsorbed equilibrium amount (P(e)) (C(e)/P(e)) and C(e), we concluded that the adsorption of Cu2+ to the porous chitosan beads was Langmuir adsorption. The Cu2+-loaded porous chitosan beads were stable in water, which is useful for further study on selectively adsorption of IgG. The results suggested that the porous chitosan beads were useful adsorbents for copper ions removal in water treatment, and the Cu2+-loaded beads may be good sorbents for IgG removal in blood purification.